Phonograph reproducer



Mar.- 20, 1923.

A. K. MILLER.

PHNOGRAPH REPRODUCER.

FILED FEB. I8, 1920.

\ Illing Patented Mar. 2,0, l923.

ni'rsn STATES PATENT Terres.

ALFRED n. MILLER, or Los AivGELiis,` oaLironivLA.

iiioiioeanrn niiraonncnn.

Application filed February 18, 1920. Serial No. 359,725.

To all fic/wm it may conce/rn.'

Be it known that I, Ammin K. MiLLnn. a citizen et the United States,residing` at Los Angeles7 in the county of Los Angeles, State ot'California, have invented new and useful Improvements in PhonographReproducers, oi which the following; is a speciification.

This invention relates generally to soundboxes, being more specificallydesigned to be used as a phonograph reproducer; `but Withoutiiecessarily being limited `to use specifically as a phonographreproducer. lt Will be readily understood, after a perusal ot thefollowing' description, that the device may be used wherever sound-boxesare used t'or the purpose of trzmstorming` mechanical vibrations intosound vibrations.

For simplicity and clarity ot description l shall describe my device inits. specific form as designed tor a phonograph reproducer; stating theobjects and accomplishments ot' the invention specifically as regardingthat term ot my device. without at all intending that such description,and statement ot' the objects and features et the invention7 shall limitmy invention speci-licilly or entirely to phonograph reproducers. Asapplied to ljhonogrraph reprodncers, it is an object of the presentinvention to provide :i sound-box which Will give imjn'oved reproductiveresults. The lgeneral objects ot the invention are set forth in myprevious application Serial No. 316,039. liled Aug'. 8, 1919; and mypresent invention includes improvements upon the sound-box set forth inmy previous application, the present improvements being` along the lineof purer tone production of greater clarity; the pro` duction ofovertone qualities; and, in fact, (as applied to a reproducer)reproduction ot all the proper tone qualities which are in a phonographrecord, and to a certain extent at least. the damping out or eliminationof sounds which, although in the phonograph record1 are undesirable; andthe damping out oi minimizing` of the undesirable'sounds arising fromthe characteristic vibration of the needle-vibratori. diaphragm itself.

further and more particular object oi the `present invention is toprovide a phonograph reproducer construction `which will raccomplish thegeneral objects of this invention, and which may be easily made Withcomparatively little expense and present a pleasing exteriorappearance.` f i As between this present application and `the prior onereferred to tlie'broader and common subject matter is herein claimed;the claims of the prior application being limited to the specilic formstherein shown and not shown herein.

The various objects, and corresponding features, of my invention in itstorni as specifically applied to phonograph reproducers. Will be betterand more fully understood from the following detailed description,reference tor `this purpose being had to the accompanying 4drawings inwhich I show in detail a phonograph reproducermade in accordance with myinvention.` ln these drawings l. is a rear tace `elevation ot my.improved reproducer; Fig. 2 is a front tace elevation of the same;Fig'. 3 is a side elevation taken as indicated by line 3 3 on Fig'. 1;Fig. 4C is a side elevation taken as indicated by line 4 4: on Fig. 1;Fig. 5 is an enlarged section talien as indicated b v line on Fia'. 1;Fig. G an enlarged 'fragmentary tace elevation taken as indicated byline 6 6 on Fig. 5; Fig. 7 `is a side elevation of the part shown inFig. 6; and Fig. 8 is a detail section taken as indicated by line 8 8 onFig. 6.

In the drawings the numeral 10 designates the body ot a case havingT anexterior 'Harige 1l and an interior liange The case is formed oi thebody member 1() and ot a case member 13 which. has an exterior flange 14and an interior flange 15. The case'tit-s over the body 1() and its'liange le tits againstfiange y1l. oi". the l'iody-.ineinber. Flange 11ot the body member is on that tace ot the sound-box which l designatethe rear tace; and on this rear tace there is a flange or ilat ring' 1Gsecured by screws 1'? to `flange 11. the screws 1 7 `also serving tosecure flange 142 against iiangre 1l.

ln the iront tace ot the case there is a ilat ring or flange 18 securedby screws 19 to liange 15 oi case` meinberl. Flange 15 has around itsinner edge an annular recess 20 and one ot' the secondary .resonatingdiaphragms` is held in this `recess by ,the AliaiiQ'r-l 18.

The foregoing described construction is. in detail7 the case which l nowspecifically prefer tor `my specific preferred arrangelOO ' phragms mentof vibrating diaphagms which I will now proceed to describe. I shallalso hereinafter state the materials of which I prefer to makethevarious parts of the device, and shall also, in order to give a completeand clear idea of a specific and successful form of my invention, givethe characteristic dimensions of the parts as herein set forth. It will,however, be readily understood, that I give all of these details for thepurpose ofV nsuitable material, and the circular edge of this diaphragmis mounted in aI rubber (preferably soft rubber) mounting ring` 26 whichencircles its edge and lies on both edge faces of the diaphragm. This isclearly illustrated in the drawing. Such a mounting ring may readily bemade by slightly stretching a rubber band of appropriate circumferenceand bending the edges of the rubber band over the edge faces of thediaphragm. It is thick enough, and of suliiciently yielding qualities,to effectually prevent the vibrations of diaphragm reaching the case inany great degree. The

`inertia of the case also assists in minimizing its vibration, either bythe needle mounting or from the primary diaphragm. The vibrations of thecase being thus minimized, it is easier to insulate the secondarydiafrom vibration. This rubber mounting ring rests against the interiorflange 12 of case body 10; and is held in place by the edge of secondarydiaphragm 27 Which in turn is held in place by the flange 16, with 'arubber ring 28 and a paper ring 29 interposed between the flange and theedge of thefsecondary diaphragm. The paper ring is a filler; and bychanging its thickness-as for instance, putting in more or less thinpaper rings-the holding pressure on the rubber rings and on thediaphragms may be adjusted to a nicety. This secondary diaphragm 27 is,in this present specific embodiment and arrangement of my invention,composed` of what is ordinarily known as hard nickel silver. It is heretwo one-hundredths of an inch in thickness. Near its edge it has a bend30 extending on a circular line clear around it, so that its edgeportion 31 is somewhat offset from the main central portion of thediaphragm; so that .mounted on the case.

the effective vibrating portion of the diaphragm is more or lessdelimited at the circular bend 31. This circular bend is at such adiameter as to make the effective vibrating part of diaphragm 27 ofabout the same diameter as the effective vibrating part of primarydiaphragm 25. The rubber mountings for these two diaphragms arecompressed sutciently by the flange 16 to hold the diaphragm securely inplace; but the rubber mountings are not compressed to the eX- tent thatvibrations from one diaphragm will pass to the other through the case ordirectly through the rubber mounting 26. The secondary diaphragm is, asfar as possible, left free t0 vibrate in its own characistie mode ofvibration, vwithout being forced by vibrations which might otherwisereach it through the mountings or through the case from the primarydiaphragm 25, or which might reach it from the case itself which is moreor less set in vibration by the vibration of the needle and needle armThe form of mounting 26 prevents the edge of primary diaphragm 25touching the case; and the bend at 31 in secondary diaphragm 27 centersthat diaphragm on mounting 26 and prevents its edge coming in contactwith the case. The two diaphragms are thus mounted solely on theirrubber mounting rings and do not contact with the case at any point. f

Secondary diaphragm 27 has at its center an aperture surrounded by anipple 31n preferably integral with the diaphragm itself. `This nipple31a is of such size as to be adapted to fit over a sound arm 32, beingprovided with a pin 33 which engages with slot 34 in the sound arm, forlocking the nippleupon the sound arm. It is through the medium of thisnipple and through the medium of the secondary diaphragm 27 that thewhole sound-box is supported and mounted upon the sound arm 32; that is,the diaphragm 27 becomes itself an element in the support and mountingfor the whole sound-box. v

The other secondary resonating diaphragm 35 is formed as the bottom of acup-shaped diaphragm and chamber member 36 which has a circular andslightly conical sidewall 37 and a rim flange 38 held in a rubbermounting member 39 in annular recess 20 and under the flange 18. Rubbermounting member 39 is similar to the mounting member 26 except that itmay be smaller. It will be noted that the external diameter of rimflange 38 is such that the rubber mounting member does not touch theouter circumferential wall. of the annular recess 20; and the inner edgeof flange 18 does not touch the side wall 37 of the diaphragm member 36;so that the diaphragm member is solely and entirely mounted in the caseresults.

throughV the intervention of the rubber mounting member 89. This rubbermountingmember is only clamped tightly enough to hold the diaphragmandchamber'member 36 in place, wit-hout compressing therubber to such adegree as to transmit vibration to the diaphragm member from the case.This rubber ring 39, as well as the others, 2G and 28, is air-tight. Therubber mountings prevent air leakage around the diaphragm edges to andfrom the resonating chamber, orchambers.' It will be understood that thespace between diaphragms 25 and 27 may, of itself, or with the sound arm32, form a resonating chamber conforming in vibration characteristicswith the diaphragm 27. The cup-shaped member is preferably pressed outof the same material as diaphragm 27, and the thickness of thismaterial, and the thickness of diaphragm 35, is one one-hundredth of aninch. The diameter of diaphragm 35, it will be noted, is substantiallyless than the diameter of diaphragm 25. The fact that diaphragm 35 formsthe bottom of the cupshaped member 36 places diaphragm 35 atvv adistance from primary diaphragm 25; the case of the device and themember 36, together with diaphragme 25 and 35, enclosing` a resonatingchamber whose resonant vibration characteristics are preferably incorrespondence with theresonant vibration characteristics of diaphragm35. Using secondary diaphragme of the n'iaterial and of the thicknesseshere stated, I find that l attain very satisfactory results when thediameter of diaphragm 35 is about one ands three-eighths inches; thetotal diameter, from edge to edge, of diaphragm 25 is about one andseven-eighths inches; the distance between diaphragms 25 and 35 is aboutfive-eighths of an inch; the effective vibratory diameter' of secondarydiaphragm 27 is about one and threefourths inches; and the distancebetween diaphragms 25 and 27 is about three-sixtyfourths of an inch attheiredges. `At their centers these diaphragms may be somewhat furtherapart due to the normal iiexing of the primary diaphragm toward the leftin Fig. 5.

l find that if ll. make the case and its parts, of brass, l have areproducer that gives about the proper weight on the needle. All of theexteriorly appearing parts, with the exception of the twosecondary'diaphragme, may be plated or otherwise finished. The interiorsurfaces of thefvariousv case parts are preferably smooth finished. y

The foregoing specifies an arrangement and design that l find ltogivepvery good l have chosen these dimensions and arrangements afterlong experiment with a view 'to arriving at'the best sound productionandthe elimination of' undesirable sounds.

l l'ind that the secondary diaphragms and the resonating chamber, orchambers, selectively kresonate the primary diaphragm vibrations so asto bring out tone qualities that are ordinarily lost in reproduction...The vibration characteristics of the secondary diaphragms are purposelydifferent from those of the primary, and also preferably different fromeach other; and it is in this differencethe selective resonation-that mygood results are made, resulting in the resonation of tones thatotherwise are feeble or drowned out, and the damping olf of sounds thatare undesired.

Using my device as a sound reproducer, it is necessary to provide ameans for vibrating the primary diaphragm 25 from a record followingneedle. The record following needle is secured in the needle-holdinghead 40 in the usual manner. Head 40 has two lateral extensions 4lprovided with grooves 42 which rest on knife-edges 43. Each eX- tension4l has a transverse pin` 44; and each pin is pressed upon by thebifurcated ends 45 of a spring 46. Spring 46 is a curved flat springwhose end is held in a notch at 47; and the tension of the spring ends45 on pins 44 isy adjusted by screws 48. It will be noted that thetension of springs `46 holds the parts 41 in engagement with knife edges43; and at the same time a spring tension is applied equally to oppositesides of the vibratory axis of the system; the bifurcations 45 of eachspring pressing equally upon the opposite ends of each pin 44.Consequently, when an adjustment of the screws is made to adjust thespring tension, no substantial change is.y made in the position ofdiaphragm 25, there being no tendency on the part of the springs, whenadjusted. to more or `less tension, to throw the diaphragm into morey orless than normal tension either side of its normal central position ofrest. The parts are arranged so that the diaphragm normally standsiiexed somewhat forwardly.

'The needle head 4() has an extension 50 which carries the needle arm51. Needle arm 5l projects into the interior of the case, through thewall of member 13, and is connected with the center of primary diaphragm25, in any of the well known manners. A small aperture at 5&2 allows thepassage of the needle arm into the interior of the case.` The needle armof course does not fit the aperture tightly.v allowing room enough forthe needle arm to vibrate; but the looseness around the needle arm doesnot materially alter the substantially enclosed condition of theresonating chamber inside the case. It `simply provides that smallopeningfwhich, under any circumstances, would be required to theexterior atmosphere to keep atmospheric pressure equalized inside andoutside' the resonating chamber.

Cfr

Having described a preferred form of my invention, I claim:

l. In a sound box, a case, a primary diaphragm therein, and a pluralityof secondary diaphragme therein in spaced and resonant relation to theprimary diaphragm7 each secondary diaphragm having vibrationcharacteristics different from the others and from the primarydiaphragm.

2. In a sound box, a case, a primary diaphragm therein, and tivosecondary diaphragms therein in spaced and resonant relation to theprimary diaphragm, one on each side of the primary diaphragm, eachsecondary diaphragm having vibration characteristics different from theother and from the primary diaphragm. l 3. In a sound box, a case, aprimary diaphragm therein, and two secondary diaphragme therein inspaced and resonant relation to the primary diaphragm, one of thesecondary diaphragms being relatively thin and far-spaced from theprimary diaphragm and the other being relatively thick and close-'spacedto the primary diaphragm.

4;. yIn a sound box, a case, a primary diaphragm therein, and twosecondary diaphragms therein in spaced and resonant relation to theprimary diaphragm, one of the secondary diaphragme being of lesserdiameter than the primary diaphragm, and each secondary diaphragm havingvibration characteristics different from the other and from the primarydiaphragm.

5. In a sound box, a case, a primary diaphragm therein, and a pluralityoi' secondary `diaphragms therein in spaced and resonant relation to theprimary diaphragm, one on each side of the primary diaphragm, one of thesecondary diaphragms being relatively thin and tar-spaced from theprimary diaphragm and the other being relatively thick and close-spacedto the primary diaphragm, the thin far-spaced diaphragm being of lesserdiameter than the primary diaphragm.

6. In a sound box, a case, and vibratory diaphragm means thereinembodying an apertured vibratable vdiaphragm having mounting meansaround its aperture adaptedto be connected to a sound tube and formingthe supporting mounting for the sound box.

7. In a sound box, a case, a primary diaphragm in the case, asecondarydiaphragm in the case in resonating relation to the primarydiaphragm, the secondary diaphragm having an opening and mounting imeans around the opening adapted to engage a sound tube.

8. In a sound box, a case, a primary diaphragm therein, and tWosecondary diaphragms therein in spaced and resonant relation to theprimary diaphragm, one ot the diaphragms being impertorate andthe otherhaving an opening and a sound tube leading from the opening in saiddiaphragm, the vibration characteristics of each secondary diaphragmbeing different from each other and from the primary diaphragm.

9. In a sound box, a case, a primary diaphram therein, and a pluralityof secondary diaphragms therein in spaced and resonant relation to theprimary diaphragm, one on each side of the primary diaphragm, one ofthe. secondary diaphragme being relatively thin and far-spaced from theprimary diaphragm and the other being relatively thick and close-spacedto the primary diaphragm, the relatively thick, far-spaced, diaphragmhaving an opening, and al sound tube leading from the opening in saiddiaphragm.

10. In a sound box, a case, a primary diaphragm therein, and a pluralityof secondary diaphragms therein in spaced and resonant relation to theprimary diaphragm, one on each side of the primary diaphragm, one of thesecondary diaphragms being relatively thin and far-spaced from theprimary diaphragm and the yother being relatively thick and close-spacedto the primary diaphragm, the thin far-spaced, diaphragm being of lesserdiameter than the primary diaphragm, and the relatively thick,far-spaced, diaphragm having an opening, and a sound tube leading fromthe opening in said diaphragm.

l1. In a sound box, a case, a primary diaphragm therein, a plurality ofsecondary diaphragms therein in spaced resonant relation to the primarydiaphragm, each oit' said secondary diaphragms having vibrationcharacteristics different from those of the primary diaphragm and fromeach other; one of said secondary diaphragms enclosingl betweenitandvthe primary diaphragm a resonating chamber, and the resonantvibration characteristics of the chamber being in correspondence withthose of said secondary diaphragm.

l2. In a sound box, a case, a primary diaphragm therein, a pair ofsecondary diaphragme in the case one on each side of the primarydiaphragm, each of the secondary diaphragms having vibrationcharacteristics different from those or' the primary diaphragm and fromeach other, one of t-he secondary diaphragms being imperiorate, the'other being apertured and adapted for connection with a sound tube, theimperiorate diaphragm being relatively thin and enclosing a resonatingchamber between it and the primary diaphragm, and t-he apertureddiaphragm being relatively thick.

13. Inasoundbox, a case, a primary diaphragm ofmica, a cup-shaped memberhaving a rim and an integral flat diaphragm bottom of nickel silverconstituting a secondary diaphragm, the member `being mounted by its rimin the case with its diaphragm bottom in resonant relation to theprimary diaphragm.

14:. ln a sound box, a case, a primary diaphragm therein of mica, acup-shaped member having a rim and an integral flat diaphragm bottom ofnickel silver constituting a secondary diaphragm, the member beingmounted by its rim in the case with its diaphragm bottom in reso-nantrelation to the primary diaphragm; and the case, the cupshaped memberand the primary diaphragm enclosing a resonating chamber Whose vibrationcharacteristics correspond to those of the secondary diaphragm. y

15. In a sound box, a case, a primary diaphragm in the case, and twosecondary diaphragme therein, the secondary diaphragme being mounted insuch relation to the primary diaphragm and being of such material anddimensions as to be resonantly vibrated from the primary diaphragm, andthe vibration characteristics of the two secondary diaphragms beingdifferent from each other.

16. ln a sound box, a case, a primary diaphragm therein, a secondarydiaphragm in the case at one side of the primary diaphragm and inresonant relation to the primary diaphragm; and a resonating chamber atthe other side of the primary diaphragm, the vibration characteristicsof the primary diaphragm and of the secondary diaphragm and of thechamber each being different from cach ot the others.

17. A` sound box, embodying a case, primary and secondary diaphragmstherein, the secondary diaphragm being in resonant relation to theprimary diaphragm and having vibration characteristics different fromthose `of the primary diaphragm so that the secondary diaphragmselectively resonates the vibrations of the primary diaphragm.

18. A sound box, embodying a case, and primary and secondary diaphragmstherein, the primary diaphragm being of mica, and the secondarydiaphragm of nickel silver, and the secondary diaphragm being inresonant relation to the primary diaphragm so as to selectively resonateits vibration.

19. A sound box, embodying a case, a diaphragm therein, and a resonatingelement in resonant relation to the diaphragm, said resonating elementhaving vibra-tion characteristics such as to be resonantly vibrated fromthe diaphragm but having its vibration characteristics somewhatdifferent from those of the diaphragm so that said element selectivelyresonates the diaphragm.

' 20. A sound box, embodyinga case, a diaphragm therein, and aresonating chamber in resonant relation to the diaphragm, saidresonating chamber having vibration characteristics such as to beresonantly vibrated from the diaphragm but having its vibrationcharacteristics somewhat different from those of the diaphragm so thatsaid chamber selectively resonates the diaphragm.

ln witness that I claim the foregoing I have hereunto subscribed my namethis 2d day of February, 1920.

i ALFRED K. MLLER.

